Optical properties of lanthanide-doped RbTiOAsO(sub 4) and transition metal-doped KTiOPO(sub 4)

摘要

We have synthesized derivatives of potassium titanyl phosphate (KTP) and rubidium titanyl arsenate (RTA) where Ti has been replaced by transition metal or lanthanide ions, and K, Ti, P or O has laced by aliovalent counterions. Up to 5 mol % lanthanide ion can be substituted onto the Ti and 100 mol % substitution of other transition metals onto the Ti sites in KTP can be made. The visible spectra of these doped KTP phases are characteristic of the dopant ions, with sharp, narrow transitions resulting from lanthanide substitution and broader absorptions from transition-metal dopants. Powder second harmonic generation (SHG) intensities diminish with increased dopant concentration. Decreases in SHG intensities parallel those seen in previously studied systems. The choice of counterion substantially impacts some dopant solubilities, but generally affects SHG intensity and visible spectrum to a lesser degree. Single crystals doped with Er(sup 3+), Fe(sup 3+) and Co(sup 2+) have linear absorption coefficients in the range of 1 to 5 cm(sup (minus)1). Changes in noncritical phase matching wavelength due to anomalous dispersion are calculated to be less than 1 nm at the dopant levels tested.